Mer mfg



sept. 2o, 1927. 1,643,105A

H. J. WIEGAND RESISTANCE CONTROL APPARATUS Filed June 4, 1923 u'yi.

ATTORNEY Patented Sept. 20, 1927.

UNITED :STATES PATENT OFFHCE.

HENRY J; WIEG-AND, 'OF'MILNAUKEIl WISCONSIN, ASSIGNOR TO THE CUTLERHAM-MER MFG'. CO.: OF MILWAUKEE. WSCONSIN, A CORPORATION OF WISCONSIN.

RESISTANCE CONTROL APPARATUS.

VApplication filed June 4,

This invention relatesto resistance control appara-tus, and while notlimited thereto is particularly applicable to apparatus for voltagecontrol ofaudion valves and the As is well known-the design andvconstruction of such valves has been and at present is in a stateofrapid development and improvement, snchzchanges frequently n' involvingcorrespondingchanges in thecharacter and values of theenergy supplied totheyalvesand in the rangefofvariation of such values required .inservice. As a -result of the..foregqng certain hivhlymeritolrioustypesand constructions o control devicslor-i such. valves endf-alsc large quanti- 'ties of existingapparatns. are in danger ofobsolescence 1nnlesssv orrespndingly devel- Opedf-mdfend impreved- I",Anobjeet offthe .present invention is that of` adapti` x1g;suchpotentiallyjobsolete designs and-: apparatus to .ipresentIA andprospective needs),-

Anoth 11 ob'ectisltliatipfm .prolonging i5 and extend-ing tlie'utilityiof such designs and such apparatus witliout substantialfintninsicmodification thereof and ,with a minimum of addition thereto..

Another obfjec 3" 'and-amplifying Such existiagiypesof-apparatus, to' zidaptl the; saine .t o presentand pros- -Peciv#slee-51S@mdI alsoreducing? the-Dumber 0f elsfilntssendspae .requirements-whom centratingandggsimplifying :the: control Other objects andadyantageswill herein.-aftsrappear.. im 1 1 In the 'accompanying drawing. wherein areillustrated certain. prefer red embodiments of the ,invention` i.

'Figure 1 isa side elevational view of such f-ElgffZfisarear.e1evational view of one of the portions thereof While.,A"1

.fgFig. BfisEa-perspective vievv of-fa,

modfiedronstructen..

Referring to thedrawino'y and particularly toFigs. 1 anfd-.2t-thereofftesame illustrate associatedl individually operable .resistance controldeviceshavingsupporting elements in common andfcom}iris ing apluralityof U-shapedframef members. 5 land 6,-preferably composed'ofmetal, to be' secured to a common connecting memberl 7, preferablyconductive and of channeled formation as 1923. Serial N0. 643,328.

.shown7 by bolts or screws 8 and- 9 and to be permanently secured uponan insulating base or panel 10. Frame members 5 and 6 are adapted tosupport the variable resistance devices 11 and 12 each having suitableterminals and operating means therefor, the latter preferably includingconcentric shafts 13 and 14 penetrating thecontrolpanel 10 and providedon the oppositeside thereof with individual operating .means such asknobs 16 and 15. Indicators such as 17 may be fixed to oneor both of.said shafts for indicating the setting of the individual elementsoperable thereby.

Obviously the longitudinal llangesbf the connector 7 are-adapted tocoact^ d;ir'ectly with the adjacent edge portions of; .frame members 5and 6 for maintaining a-coplanar relation of the operatingzshaftsl and14 whereas said connector iS .,'OthelNYise' vso shaped, as shoivn,. toprovide .not only for actual parallelism of said shaftsvbutfurther toprovide and maintain a concentric or telescopic lrelation thereof,.thusagain providing for longitudinal adjustment of Asaid shafts andpreventing operative interference thereof.4

The resistance devices 11 and: 12 comprise generally, resistor coilslltand 19 mounted respectively upon rotatable members'Q and 21, therotatable members 2 05inc1uding a Circumferentially grooved annular'insulating member; to receive and-,'hold the resistor coil 18 in spacedrelation .with respectto the metallic end capsof the member 20;whercasthe rotatable member 2li-.comprises a-pair of insulatingdiskshavingnpon their adjacent faces and adjacenttthe .'respectiveperipheries thereof inwardly Afacing..annular grooves to receive thel(resistor-.element 19 the latter comprisinga. relatively large numberof. turns Ofiline resistancejvire .wound .upon a flexible strip-of fibreor other suitable insulating' material. Each of said coilshas llODetails of said resistance devicesare disclosed and claimed in mycopending-applications, S. N. 561,136, tiled May 15, 1922 3nd S. N.622,078 tiled March l, 1923, and

'. hence further description herein of these elemanner Whereas theelement 1l is also Se cured to the concentric shaft 22 and suchsecurement of said element may be conveniently cll'ected b v means ofthe usual set screw 23 acting through and upon hub portion 24 and alsopenetrating a suitable opening in tubular shaft and producing a clampingaction on said shaft 13.

An auxiliary resistance element 25 of suitable or desired ohmic value issecured to the resistance device to be in circuit therewith. In practicesaid resistance element 25 may preferably comprise' a coil 26 of arelatively` large number of turns of resistance Wire 2. said wire beingpreferably Wound upon a liexible strip 28 of fibre or other suitableinsulating material and terminally anchored thereto,- one end of saidresistance wire being so anchored preferably by means of annet-algrommet 29 said grommet serving as a mounting means for one end of theresistance element while theopposite end is rovided with an aperture 30.In 'mounting said resistance element 25, as shown in Fig. 1, the endhaving the grommet therein is secured to and upon the terminal device 31and said strip- 28 having the resistance element 25 coiled vthereon isthereafter bent or bowed to bring the aperture 30 into register 'withb'olt S and`is thereafter secured by'nut 32;

In Fig. 2 is shown a modified form of mounting means for one end of thea-uxil# iar'y resistance element 25, the-same comprisingaplate member 33provided with a screw threaded opening 34 for the reception ot` Screw 35and having a. projection 36 loosely 'connecting plate member 33 toflexible strip 28l thereby providing,lr limited movement of said platemember 33, the same actin: as a nutfor mount-ingr the endof the resistorelement- 25 to frame member 5 as before described."This methodfacilitates mounting o'f the auxiliary resistance element,v it beingreadily seen' that such operation-may he accomplished Wholly fromWithout the frame` without involving disassembly of any part of thedevice.

The value of the resistance of the element 25 to be included in circuitmay be varied by means of a slider 37 having one lead of the controlledcircuit connected thereto. Said slider in practice may preferablycomprise a metal strip -formed as best shown in Fig. 3. havingr portions38 bent as shown not only to support the same but also to make contactwith the resistance 27. A clamping screw 39 is provided lin theoutstruck portion 40, said screw 39 being provided with a nut 4l forlocking the slider in the desired position and also with a terminaldevice 42. The resistance element is to be in circuit with element 11and such joint circuit may be traced from the terminal device of slider37, through that portion of the resistance 26 determined by thepositioning of said slider to terminal device 31 by Contact finger 43 toand through resistance 18 or through the portion thereof determined bythe rheostat setting and't-henc'e to frame 5 and its associatedterminal.

Referring now to Fig. 3,- th'e same illustrates a pair of mainresistance varying elements similar to the eleme'nt 11, arranged,connected and supported for independent operation in the manner'afrede's'cribed.

One or both of said main resistance ele'- ments is in this instanceprovided with an auxiliary resistance element 25a `which is functionallysiniil'ar'-to tlie' corres; ending' `element 25 aforedescribed butwillich' is modified in matters of structure, dimensions, ctc., betterto adapt the same' to certain special requirements` and conditions.

In this arrangement the rheostat terminal device 44 alone is adapted toprvide both for mechanical support and electrical connection ofthe"ele`1'nent 25; iyh'erby, the angular position of said element withrference to the rlieo'stat frame may 'bevaried at will to suit theconditions of any particular installation.

It is of course to be' understood that the auxiliary resistance elements25 and 25* may be substituted n for lthe 'otlierjand that either mayvberep'lac'eda mechanically similar unit having e diffrent olimic orother electricalvalue "vvlienyernecs's'igy or desirable in' o'rd'er todapt the device, either electrically ordnecli-iiicallytoa particularinstallation. Also it is Vto be observdthat in accordance v'vitli thepi-snttacliiniipractically any desired number of independently operable;resistance orpotential controlling devices4 :or both may bearrg'd'fftioint electrical connection and mechanica] supi Port. i Again`optionally'- as shoivn inFig". '3, Sima 13' may be censfmcfdfofiasuiaungmaterial as indicated at 13 and franie'nl'ay be insulated' fromcon'r'iector-'7a 'as tin insulating bushing 45, whereby the individualresistance varying deic'es may be"a"dapted to controlelectricallyindependnt circuits. Thus if desired all tlie resistance andpoten- .ial control instrumentalities of a co'tnplet'e installation maybe arranged Within vap-l proximately the same mounting area ordinarilyoccupied by a single instrumentality.

What. l claim as new and desire to secure by Letters Patent is liu ` forzsuiistninniy l., In resistance. control apparatus, the combination withaself sup ort-ingrheostat to'be secured to a base, o an attachmentaugmenting the total ohmic :value ofsaid rvheostlt, comprising anauxiliary flexible resistor devieeand ter- 'gmlnal means. providing' iffonarcuate positioningiof the latter aboutsaid rheostat and 1 11circuit with -the.- resistor :element thereofA2.3In.resistance.@ntrol.apparatus, the

cemhnation; Withnef rheostat v having associated supporting means, of anattachment .for substant-ially augmenting A the. total ohmiq-valueof-sa'id rheostat comprising an. aux

iliaryzaierble:fresistpriidevce having tef- 2" .auxilianynresistereaboutsaid rheostatand latedisgpporting means, of an -attachn'ientAsubstant1g,l ly;y -;augmenting the total fphx'nicj value pf.saidwrlieostan `comp rising an auxiliary flexible resisfordevice'having ter- .-minalmeans including ayrigidlysecured ter- .minaldevichavlngparts'ito cooperate directly.with isad; nheostat, 1supporting means ,-to uprovide; fox: 'a arcuate; positioning Aof said.aiuxl-liany-re'sistorabout said 'rheostat and for ,terminal-fconnection .thereof in ci rcui t with 'saidIrheostag saidjauxiliaryresistor Ehavingnneans .fompreselectng the effective1olunic;value-thereof., i; g5 -4 v .resistance 'control: apparatus, thecombination? with;.-.a'rheostat having. asso--icia-tedfs'upportingvmeans, of an attachment for substantiallyaugmenting the total ohmic value of'said-rheosta-t, comprising anauxiliary Hexible" resistor device having terninal means including anadjust-ably fixed slidenand a terminal device rigidly secured theretofor mechanical support and arcuatepositioningr Tof'said gauxiliaryresistor about and in circuit 'with said rheostat.

5. In resistance control apparatus.l the combination with a rheostathaving associated supportingr means, of an attachment for substantiallyaugmenting the total ohmic value of said rheostat, comprising anauxiliary fiexible resistor device having terminal means including anadjustably fixed clamping slider and a rigidly secured terminal devicefor mechanical support and securement of said auxiliary resistor to andin circuit with said rheostat, in a relation providing for angularadjustment of the position of said auxiliary resistor with respect tothe associated supporting means of said rheostat.

6. ln resistance control apparatus, the combination with a plurality ofresistance varying devices having individual operating means andindividual conductivesupporting frames to lie included in the controlledcircuit` said frames having similarlyudisposed openings.` of anelongatedconnector to be terminally` secured to said framesadjacent toand in association with saidopenings for rigidly uniting andelectrically .con-

Vnecting said devices, certain of thezflatter having means for ,securing.the samexupon -a4 base to .thereby provide 4 for eommongsupportl of allthedevices .so united theretosfg 7; In resistance control apparatus,'.the combina tion with .a plurality off-.resistance varying deviceshaving individual operating means and individual conduetivesupportingframesto he included in thegcontrlledircuit, said frames having-similarlygdisposed openings, of van elongated xconductive :bon-

nectorA a1id.mea.ns to co-operateqwithifsaid :51

openings for rigidly unitingtandfeleetnicalnector, certain of4 saiddevices :ha-Ying' means .for securing the'same uponga basegtotherebyprovide ioi common-support.of.iallfthe devices so united. saidoperating. means-.be-

inf- T arranged and correlatedio'prowidea for close juxtaposition of theindividualoperating members while maintainmglndependence of actionthereof. 1; u igui 8. In yresistance coutrolappajratus,Ahe

combination with a plurality .of-resistance varying devices. havingindependentasapporting frames and individual (operating means: of arigid har and meansfor-sec'uring said frames thereto .for mechanicallyuniting said devicesin a relation providing for close. juxtaposition otcertaino stlxeii' respective operati ng elements, said-bar having itslongitudinal edges shaped to co-operate with adjacent portions ofVthe'respective frames for maintaining parallelism of said juxtaposedoperating elements to thereb v minimize operative interferencetherebetween.

9. ln resistance control apparatus, the combination with a plurality ofresistance varying devices having independent s'up-i porting frames andindividual operating means, of a rigid metallic har and means forsecuring said frames thereto for electrically connecting andmechanically uniting said devices in a relation providing for closejuxtaposition of certain of their respective operating elements said barbeing shaped to co-operate with adjacent portions of said individualframes for maintaining a relation of said juxtaposed operating elementswherein operative interference therebetween is minimized` 10. Inresistance control apparatus, the combination with a plurality ofresistance ,loo

varying devices having independentconduc-v electrically connecting thelatter` each of said supports having a portion extending in parallelrelation to a given axis of its assoeiated resistance con-trol device,said means oomprisin" parts to coot with said parallel extendingportions of said 'supports for maintaining -a coplanaarrangement of saidaxes, certain of said supports having means to provide -for mountingupon a common base of all the devices so united.

12. In resistance control apparatus, the combination with a pluralityofv resistance Varying devices having independent sup ports, of means tocoact with the supports of said devices for mechanically uniting andelectrically connecting' the latter. each of said supports having edgeportions extending in parallel relation to a given axis of itsassociated resistance control device, said means comprising paralleledge portions to coact fwth the aforementioned edge portions of saidsupports for maintaining coplanar relation of said axes and said meansbeing so formed as to maintain said axes Within a common plane angularlyrelated to said former plane, certain of said supports having' means toprovide for mounting upon a common base of all the devices so united.

13.|In resistance control apparatus', the combination with a pluralityof resistance varying devices having independent supports, andcorrespondingly disposed operating shafts, of means to coact with thesupports of said devices for mechanically uniting and electricallyconnecting the latter,

each of said supports having edge portions extending in parallelrelation to the respective operating shaft of its associated resistancecontrol device, said means comprising parallel edge portions to coactwith the aforementioned edge portions of said sup'- ports formaintaining coplanar relation of said operating shafts and said meansbeing further 'so formed as to provide foi` maintaining telescopicrelation of said shafts to thereby provide for relativev airialadjustment thereof.

14. In resistance control apparatus, the combination with a plurality ofresistance varying devices having independent substantially U-shapedmetallic supports, of moans; to coaot with the supports of said devicesfor ymechanioally uniting the latter, each of said supports having edgeportions eil-tending in parallel relation te the eperat- 'ing 'shaft ofits associated resistance control device, said means comprising paralleledge .portions to ooaot with the aforementioned edge portions of saidsupports -for niaintaining parallel relation of said axes, certain ofsaid supports having means to'prvide for mounting upon a common base ofall the devices so united.

' l5. 'In resista-nce control apparatus, the combination with 'ai'rhe'ostatt having associated supporting means. of an attachment forsubstantially augmenting the total ohmic value of sziid rhe'ostatcomprising an uXilliary resistor device having terminal means includinga rigidly secured terminal device having parts to cooperate directlywith said rheostat supporting means to provide both mechanica-l supportand terminal connection of said auxiliary resistor device in circuitwith said rheos'tat, said resistor device being of flexible constructionto provide for arcu ate positioning thereof with respect to saidsupporting means and in radially spaced relation to said rheostat.

In Witness whereof, I have hereunto subscribed my name.

HENRY J. VVIEGAND.

